Background

Three projects are available starting in 2013 under the theme of climate change and physiological ecology. These projects form part of a broader research program which investigates the potential of ectotherms to buffer climate change via microsite selection, shifts in metabolic costs, and the plasticity of locomotor performance. By integrating theoretical and empirical approaches, this project will improve the formulation of a predictive model of thermoregulation based on energetic gains and losses coupled with climate variability. It also addresses the potential effects of climate change and plant invasions on habitat thermal quality of ectotherms.

Projects

• Test the predictions and assumptions of the cost-benefit model of thermoregulation in the laboratory using an insect model system.
• Test the predictions and assumptions of the cost-benefit model of thermoregulation in laboratory and field settings using a lizard model system.
• Assess if lizard communities differ between native habitat and sites invaded by alien plants in the Western Cape Province, and test if the loss of thermal habitat quality may explain shifts in species composition, richness and abundance.

Key contacts

Interested candidates should send applications by email to Susana Clusella-Trullas: sct333@sun.ac.za and see http://clusellatrullas.blogspot.com/ for additional information.

Applications should include a cover letter stating motivation for doing the project, an updated academic CV including exam transcripts and contact information (telephone and email) of two referees.

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Background

Several of the most widespread and damaging invasive plant species in South Africa come from the genus Acacia (in particular Acacia baileyana; A. dealbata; A. decurrens; and A. mearnsii). However, little is understood about the introduction history (e.g. number of independent introductions, origins of introductions, etc.) and infra-specific identities of the invasive population. Understanding the source population of a weed is being increasingly recognised as a core component in the search for classical biological control agents (Goolsby et al. 2006). National weed management plans and weed risk analyses often use case studies or data in one part of the country to inform strategies in another part, but this may ignore underlying population genetic structure that would be expected to change through time. The success of climate matching in projecting risk also assumes uniform intra-specific variation either within in the introduced range through time, or between the introduced and native ranges. Many wattles have been introduced for agro-forestry purposes to South Africa and have been planted extensively in monocultures. An additional focus of this research project would be to determine the role of these plantations in facilitating invasions, i.e. act as sources of propagules. This project will be part of a major research focus of the C·I·B on Australian Acacia introduction both in South Africa and around the world.

This is a project suitable for students interested in molecular biology, evolutionary biology, ecology, and social history that want to work as part of an inter-disciplinary team. The candidates have to be willing to spend periods working in Australia.

Key contacts

• Dr Jaco Le Roux, Centre for Invasion Biology, Stellenbosch University (jleroux@sun.ac.za)
• Dr John Wilson, South African National Biodiversity Institute / Centre for Invasion Biology, Stellenbosch University (jrwilson@sun.ac.za)
• Prof David Richardson, Centre for Invasion Biology, Stellenbosch University

Further reading:

• Goolsby, J.A., De Barro, P.J., Makinson, J.R., Pemberton, R.W., Hartley, D.M., Frohlich, D.R., 2006. Matching the origin of an invasive weed for selection of a herbivore haplotype for a biological control programme. Molecular Ecology, 15, 287-297.
• Ellstrand NC, Schierenbeck KA (2000) Hybridization as a stimulus for the evolution of invasiveness in plants? Proceedings of the National Academy of Sciences of the United States of America, 97, 7041–7050.
• Le Roux, J. J., Brown, G. K., Byrne, M., Ndlovu, J., Richardson, D. M., Thompson, G. D. & Wilson, J. R. U. (2011) Phylogeographic consequences of different introduction histories of invasive Australian Acacia species and Paraserianthes lophantha (Fabaceae) in South Africa. Diversity and Distributions, 17, 861–871.
• Le Roux, J. J. & Wieczorek, A. M. (2009) Molecular systematics and population genetics of biological invasions: towards a better understanding of invasive species management. Annals of Applied Biology, 154, 1–17.
• Prentis, P. J., Wilson, J. R. U., Dormontt, E. E., Richardson, D. M. & Lowe, A. J. (2008) Adaptive evolution in invasive species. Trends in Plant Science, 13, 288–294.
• Richardson, D. M., Carruthers, J., Hui, C., Impson, F. A. C., Miller, J. T., Robertson, M. P., Rouget, M., le Roux, J. J. & Wilson, J. R. U. (2011) Human-mediated introductions of Australian acacias — a global experiment in biogeography. Diversity and Distributions, 17, 771–787.

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Background

Acacia cyclops, commonly known as Rooikrans, was introduced to South Africa on at least two occasions and in very high numbers for dune stabilization. It quickly became one of the most noxious and dominant invasive species in western and southern coastal areas in South Africa, and is now considered a transformer species occupying a vast range, especially in the fynbos biome.

The proposed research aims to elucidate how contemporary forces of evolution such as admixture between previously allopatric gene lineages and strong genetic drift influence the overall fitness of Acacia cyclops in South Africa and its interactions with one of its biological control agents, the cecidomyiid gall midge, Dasineura dielsi Rübsaamen. Invasive species are often treated as evolutionary-uniform entities, i.e. all native populations share the same evolutionary history, and therefore the same biotic and abiotic interactions. This may seriously hamper theoretical and practical understanding of species interactions as these are never uniform across species distributions. The proposed research will therefore not only inform theory on spatial and temporal variation in plant-animal interactions but can also be applied to sciences related to biological control of invasive plants in general.

This research project will use a population genetic approach to (1) Determine the fine-scale native range provenances in Australia of invasive A. cyclops populations in South Africa, (2) Determine the spatial extent of admixture within South African populations and (3) to determine whether evolutionary co-diversification occurred between A. cyclops and D. dielsi in Australia. Data from aims 2 and 3 will be used to test whether any correlation exists between agent (D. dielsi) and host interactions in the field in South Africa and levels of admixture. Lastly, by growing plants obtained from throughout South Africa and Australia under common garden conditions, the proposed research will aim to (4) elucidate the evolutionary consequences of admixture on invasiveness, specifically testing for EICA.

Key contacts

• Dr Jaco Le Roux, Centre for Invasion Biology, Stellenbosch University (jleroux@sun.ac.za)
• Prof David Richardson, Centre for Invasion Biology, Stellenbosch University
• Dr John Wilson, South African National Biodiversity Institute / Centre for Invasion Biology, Stellenbosch University (jrwilson@sun.ac.za)

Further reading:

• Blossey, B., and Nötzold, R. (1995) Evolution of increased competitive ability in invasive nonindigenous plants: a hypothesis. Journal of Ecology, 83, 887-889.
• Keller, S.R. and Taylor, D.R. (2008) History, chance, and adaptation during biological invasion: separating stochastic phenotypic evolution from response to selection. Ecology Letters, 11, 852-866.
• Le Roux, J. J., Brown, G. K., Byrne, M., Ndlovu, J., Richardson, D. M., Thompson, G. D. & Wilson, J. R. U. (2011) Phylogeographic consequences of different introduction histories of invasive Australian Acacia species and Paraserianthes lophantha (Fabaceae) in South Africa. Diversity and Distributions, 17, 861–871.

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Background

“One’s ideas must be as broad as Nature if they are to interpret Nature” – AC Doyle (1887)

The structure of regional ecological assemblages or communities reflects the interplay of multiple ecological, evolutionary and environmental processes working at different temporal and spatial scales. Macroecology is the study of patterns emerging at broad scales and their potential mechanisms. Biological invasion, as an important macroecological processes, has been recognized as one of the eminent drivers of biodiversity loss. Invasive organisms introduced from their native species assemblage into a novel community perform differently. Such difference in the invasiveness could have already been exhibited in the macroecological patterns in both the native and invaded communities. Pilot studies of Australian Acacias from our team have suggested that macroecological patterns of species distributions can, to a certain degree, indicate species’ invasiveness. This PhD project will thus be to place the macroecology in a phylogenetic context and further explore the potential linkage of species invasiveness to the macroecological patterns of other major traits and niche differentiation.

This project will be part of a major research focus of the C·I·B on Australian Acacia introductions both in South Africa and around the world. Students who are interested and competent in spatial, community, global, or computational ecology are cordially invited to apply.

Key contacts

• Dr Cang Hui, Centre for Invasion Biology, Stellenbosch University (chui@sun.ac.za)
• Prof David Richardson, Centre for Invasion Biology, Stellenbosch University
• Dr John Wilson, South African National Biodiversity Institute / Centre for Invasion Biology, Stellenbosch University (jrwilson@sun.ac.za)

Further reading:

• Brown JH. (1995) Macroecology. Chicago U Press, Chicago.
• Gaston KJ, Blackburn TM (2000) Pattern and process in macroecology. Blackwell, Oxford.
• Hui, C., Richardson, D. M., Robertson, M. P., Wilson, J. R. U. & Yates, C. Y. (2011) Macroecology meets invasion ecology: linking native distribution of Australian acacias to invasiveness. Diversity and Distributions, 17, 872–883.
• Richardson, D. M., Carruthers, J., Hui, C., Impson, F. A. C., Miller, J. T., Robertson, M. P., Rouget, M., le Roux, J. J. & Wilson, J. R. U. (2011) Human-mediated introductions of Australian acacias — a global experiment in biogeography. Diversity and Distributions, 17, 771–787.
• Storch D, Marquet PA, Brown JH (2007) Scaling biodiversity. Cambridge U Press, Cambridge.

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Project description

This project will form part of an exchange programme with a number of other students working on ecological networks in natural vegetation and mango orchards. This particular project will investigate how alien plants have infiltrated food webs around the mango plantation area in Limpopo province, between Orpen Gate (Kruger Park) and the Blyde River Canyon. The project’s focus will be on how alien plants may have developed mutualisms with generalist pollinators and how they may also provide resources for crop pests and their predators and parasites. Ecological networks will be used to investigate the extent and importance of these interactions for both indigenous vegetation and mango orchards.

Academic Institutions

This project is a collaboration between the Centre for Invasion Biology at the University of Stellenbosch, South African National Biodiversity Institute, in South Africa, and the Universities of Exeter (Cornwall campus), Pierre and Marie Curie (Paris) and NCB-Naturalis (Netherlands) in Europe. The successful candidate will spend some time in Cornwall and Paris as part of a student exchange programme.

Requirements

We are looking for South African citizens with an Honours degree and a good academic record in ecology. The project will involve a fair amount of field work, and so we’d like the candidate to be able to work independently, and be well organised. The candidate is required to have a valid driver’s license, and be willing to spend some time in Europe as part of an exchange programme.

Offer

The qualifying student will be able to apply for a CIB bursary and operational costs, including flights, transport and accommodation with some living allowance for Europe is included in the offer.

How to apply

Please send a written application with a cover letter (no longer than 2 pages), a CV that includes your academic record, any scientific publications on which you have been an author, and proof of your ability to be organized and work independently (no longer than 3 pages), academic transcripts and the names of at least two academic referees. Please submit your application by 31 October 2012.

Key contacts

A detailed project proposal or further information can be obtained from Dr. Colleen Seymour (c.seymour@sanbi.org.za) or Dr. John Wilson (jrwilson@sun.ac.za.

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Background

The movement of plants around the world by the horticultural trade has historically been one of the major proximate causes of biological invasions. Legislation is currently being amended in South Africa as part of the National Environmental Management: Biodiversity Act to restrict the use of and trade in species that pose a high invasion risk to South Africa. One recommendation is that cultivars of species listed as invasive (or potentially invasive) that have an acceptable invasion risk (e.g. through sterility) are explicitly specified in and exempt from the regulations.

The purpose of the studentship would be to develop tests that are necessary and sufficient to allow the cultivation of plants that would otherwise be regulated under NEM:BA. This would involve experimental tests of particular cultivars, an in-depth analysis in a particular group, and the development of a risk assessment protocol. They would also potentially shed light on species boundaries in plants. As such it is expected to produce both practical guidelines, and evolutionary insights that are publishable in top international journals. The project has the potential to link with the Early Detection and Rapid Response program of SANBI.

This is a project suitable for students interested in molecular biology, evolutionary biology, ecology, and horticulture.

Key contacts

• Dr John Wilson, South African National Biodiversity Institute / Centre for Invasion Biology, Stellenbosch University (jrwilson@sun.ac.za)
• Dr Jaco Le Roux, Centre for Invasion Biology, Stellenbosch University (jleroux@sun.ac.za)
• Prof David Richardson, Centre for Invasion Biology, Stellenbosch University

Further reading:

• Dehnen-Schmutz K, Touza J, Perrings C and Williamson M (2007) A century of the ornamental plant trade and its impact on invasion success. Diversity and Distributions 13: 527-534
• Pemberton RW and Liu H (2009) Marketing time predicts naturalization of horticultural plants. Ecology 90: 69-80
• Reichard SH and White P (2001) Horticulture as a pathway of invasive plant introductions in the United States. BioScience 51: 103-113
• Wilson RL and Hoch WA (2009) Identification of Sterile, Noninvasive Cultivars of Japanese Spirea. HortScience 44: 2031-2034

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Background

Earthworms play a major role as ecosystem engineers in both natural and agricultural systems. They are also increasingly being used for soil improvement, composting, waste disposal, and as bait for angling. However there has been no scientific assessment of whether these uses pose a risk to South African biodiversity. Moreover, South Africa is known to have a unique earthworm fauna which is yet to be fully documented, and as such building capacity to conduct earthworm research over the medium term is an urgent priority for natural resource management.

The first two PhD projects will involve assessments of the diversity and distribution of native and alien earthworms in several threatened biomes: fynbos, Afro-montane forest, grassland & savanna. This research will include detailed surveys of earthworms in landscape scale transects moving across land-use types including urban, peri-urban, agricultural and natural systems in two regions of South Africa: the Cape Floristic Region and in KwaZulu-Natal.

The third PhD will involve an assessment of the introduction of and trade in earthworms in South Africa. This work will assess which earthworms are currently being actively used in South Africa and appraise introduction routes (both deliberate and accidental) and current introduction rates by taking samples from vermiculture and other relevant industries (e.g. soil in potted plants used in horticulture). It will include an in-depth study of domestic vermicomposting (samples in gardens with different users who have practised vermicomposting over different number of years) and explore the socio-economic drivers of the industry. In collaboration with local authorities and stake-holders the project will produce guidelines for the public.

Key contacts

• Dr. Sandi Willows-Munro, University of KwaZulu-Natal, (willows-munro@ukzn.ac.za)
• Dr John Wilson, South African National Biodiversity Institute / Centre for Invasion Biology, Stellenbosch University (jrwilson@sun.ac.za)

Further reading:

• Copley, J. (2000) Ecology goes underground. Nature, 406, 452-454.
• Hendrix, P. F., Callaham, M. A., Drake, J. M., Huang, C. Y., James, S. W., Snyder, B. A. & Zhang, W. X. (2008) Pandora's Box contained bait: the global problem of introduced earthworms. Annual Review of Ecology Evolution and Systematics, 39, 593-613.
• Lavelle, P., Decaens, T., Aubert, M., Barot, S., Blouin, M., Bureau, F., Margerie, P., Mora, P. & Rossi, J. P. (2006) Soil invertebrates and ecosystem services. European Journal of Soil Biology, 42, S3-S15.
• Plisko, J. D. (2010). Megadrile earthworm taxa introduced to South African soils (Oligochaeta: Acanthodrilidae, Eudrilidae, Glossoscolecidae, Lumbricidae, Megascolecidae, Ocnerodrilidae). African Invertebrates 51, 289–312.
• Wardle, D. A., Bardgett, R. D., Klironomos, J. N., Setala, H., van der Putten, W. H. & Wall, D. H. (2004) Ecological linkages between aboveground and belowground biota. Science, 304, 1629-1633.

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Background

The North-East Pacific acorn barnacle Balanus glandula has recently been recognised as an invasive alien species along the South African coast (Simon-Blecher et al. 2008). Currently restricted to the west coast, this species occupies approximately 400km of coastline between Elands Bay and Misty Cliffs (Laird & Griffiths 2008). Despite recognition of this barnacle as a dominant species in the mid shore zone (Laird & Griffiths 2008), to date no information exists on the impacts of B. glandula on South African shores.

The spatial dominance of this alien leads to questions regarding what factors may be governing competitive interactions between B. glandula and indigenous barnacles. In other regions of the world Balaniod barnacles are often dominant on rocky shores due to their high relative growth rates, superior feeding mechanisms, tubiferous wall structure and very high fecundity (Hui & Moyse 1987). By the same token barnacle populations are often controlled by predation (Stanford & Swezey 2008).

Within the context of the B. glandula invasion of the South African west coast the following questions arise:

1. Why has predation pressure failed to prevent a rapid spread of B. glandula?
2. Does B. glandula show superior growth rates and shell condition than indigenous species?
3. What role do wave action and upwelling play in regulating competitive interactions between the various barnacle species?
4. Does B. glandula have a lower thermal tolerance than indigenous barnacles and is it able to survive on the south coast?

By considering these questions this project will provide an understanding of how B. glandula has achieved dominance of the mid-shore along the west coast while enabling predictions about the spread and potential impacts of this species along the south coast.

Key contacts

• Dr Tammy Robinson, Centre for Invasion Biology, Stellenbosch University (trobins@sun.ac.za)

Further reading:

• Kado R 2003. Invasion of Japanese shores by the NE Pacific barnacle Balanus glandula and its ecological and biogeographical impact. Marine Ecology Progress Series 249: 199-206.
• Laird MC, Griffiths CL 2008. Present distribution and abundance of the introduced barnacle Balanus glandula Darwin in South Africa. African Journal of Marine Science 30: 93-100.
• Simon-Blecher N, Granevitze Z, Achituv Y 2008. Balanus glandula: from North-West America to the west coast of South Africa. African Journal of Marine Science 30: 85-92.
• Stanford E, Swezey DS 2008. Response of predatory snails to a novel prey following the geographic range expansion of an intertidal barnacle. Journal of Experimental Marine Biology and Ecology 354: 220-230.

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Background

The WfW Programme follows a contractor development approach, according to which one aim is to train and empower its beneficiaries to become entrepreneurial, independent contractors. Recently, WfW has started to draft a policy that would allow them to engage with private land-users to eradicate invasive alien species on private land. This development implies that WfW’s contractors would be expected to tender for IAS-clearing contracts on private land, as well as interacting closely with private land-users. This will create a market for clearing IAS in the Western Cape in which contractors can be absorbed, and therefore has the potential to create future employment for WfW beneficiaries outside of what is currently provided by government. However, the degree to which contractors would be willing to avail themselves of this opportunity, as well as the extent to which contractors and private land-users would be able to co-operate successfully in the clearing of IAS, have not yet been considered empirically. A study on the barriers and challenges to working on private land from the contractors’ perspective would assist the WfW Programme in developing policy that would effectively guide their approach to the clearing of invasive alien species on private land.

Key contacts

• Dr Heidi Prozesky, Centre for Invasion Biology, Stellenbosch University (hep@sun.ac.za)

Further reading:

• Buch, A. & Dixon, A. 2008. South Africa’s Working for Water Programme: Searching for win–win outcomes for people and the environment. Sustainable Development, 17(3):129–141.
• Cichello, P.L. 2005. Hindrances to self-employment activity: evidence from the 2000 Khayelitsha/Mitchells’s Plain survey. Cape Town: Centre for Social Science Research.
• Magadlela, D. & Mdzeke, N. 2004. Social benefits in the Working for Water programme as a public works programme. South African Journal of Science, 100(1/2):94–96.
• Surender, R., Noble, M., Wright, G. & Ntshongwana, P. 2010. Social assistance and dependency in South Africa: an analysis of attitudes to paid work and social grants. Journal of Social Policy, 39(2):203-221.

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Background

This research would fall primarily within the ambit of science and technology studies, with a focus on the role scientific research on IAS plays with regard to agenda setting in environmental policy (within government, NGOs, industry, and/or academia), and/or environmental planning relating to IAS (on national and local levels). However, the diffusion of scientific knowledge on IAS (among the broader public, social movements, etc.) and/or a study on the mass-media coverage of the IAS issue may be of interest to students drawn to the sociology of communication. A detailed content analysis of a selection of articles contained in an existing database of almost two decades of South African research on IAS may serve as a foundation for such research.

Key contacts

• Dr Heidi Prozesky, Centre for Invasion Biology, Stellenbosch University (hep@sun.ac.za)
• Prof Karen Esler, Centre for Invasion Biology, Stellenbosch University (kje@sun.ac.za)

Further reading:

• Briggs S.V. 2006. Integrating policy and science in natural resources: why so difficult? Ecol Manage Restor 7:37–39
• Esler, K., Prozesky, H. E., Sharma, G. P. & McGeoch, M. 2010. How wide is the “knowing-doing” gap in invasion biology? Biological Invasions. Doi 10.1007/s10530-010-9812-x.
• Gibbons, P., Zammit, C., Youngentob, K et al. 2008. Some practical suggestions for improving engagement between researchers and policy-makers in natural resource management. Ecol Manage Restor 9:182–186
• Higgs, E. 2005. The two-culture problems: ecological restoration and the integration of knowledge. Restor Ecol 13: 159–164
• Larson, B. M. H. 2007. An alien approach to invasive species: objectivity and society in invasion biology. Biol Invasions 9:947–956
• Pohl, C. 2008. From science to policy through transdisciplinary research. Environ Sci Policy 11:46–53
• Roux, D.J., Rogers, K.H., Biggs, H.C. et al. 2006. Bridging the science-management divide: moving from unidirectional knowledge transfer to knowledge interfacing and sharing. Ecol Soc 11:4 [online] URL: http://www.ecologyand society.org/col11/iss1/art4/
• Shackleton, C., Cundhill, G., Knight, A. 2009. Beyond just research: experiences from southern Africa in developing social learning partnerships for resource conservation initiatives. Biotropica 41:563–570
• Shanley, P., López, C. 2009. Out of the loop: why research rarely reaches policy makers and the public and what can be done. Biotropica 41:535–544
• Shaw, J. D., Wilson, J. R. U., Richardson, D. M. 2010. Initiating dialogue between scientists and managers of biological invasions. Biol Invasions. doi:10.1007/s10530-010-9821-9

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Background

Invasive species are ultimately the result of human choices and actions, and humans have an important role to play (whether accidentally or intentionally) in determining which species grow where. As such, biodiversity value, particularly that of transformed environments, is a function of social variables. More directly, the ability to manage, for example, a river (including its water flow rates and flood prevention) is determined by how people view biodiversity. Students interested in social attitudes towards IAS could join students and staff at the DST-NRF Centre of Excellence for Invasion Biology in a long-term inter-disciplinary project on the management of “Stellenbosch University's River&rdquo, the Eerste River. This would imply linking their research to a a longitudinal case study of the changing stresses upon the river system, with a particular focus on an invasive alien plant, Acacia implexa. As changes in stresses are highly dependent on changes in attitudes and actions of the people who interact (whether intentionally or accidentally) with the river system, it is necessary to complement the time series of the biological data with social research aimed at answering questions such as the following: Which species are people growing, and how do they view the effect of their actions? How do they view efforts to control or manage particular species? What function they want the river to serve? Do they know the ecological state of the river? The student will therefore be expected to collect base-line data on people's perceptions and usage of the water-way, to allow for on-going assessments of changes in such orientations and behaviour. Ultimately, the research should also be aimed at informing practical management and to demonstrate potential, tangible actions related to the eradication of Acacia implexa.

Key contacts

• Dr Heidi Prozesky, Centre for Invasion Biology, Stellenbosch University (hep@sun.ac.za)

Further reading:

• Meek, C. S., Richardson, D. M. & Mucina, L. (2010) A river runs through it: Effects of land use on alien plant composition along a riparian corridor in the Cape Floristic Region, South Africa. Conservation Biology, 143, 156-164.
• Simberloff, D. (2009) We can eliminate invasions or live with them: successful management projects. Biological Invasions, 11, 149–157.
• García-Llorente, M., Martín-López, B., González, J. A., Alcorlo, P. & Montes, C. 2008. Social perceptions of the impacts and benefits of invasive alien species: implications for management. Biological Conservation 141, 2969-2983.
• Kaiser, F. G. , Wölfing, S. & Fuhrer, U. (1999). Environmental Attitude and Ecological Behaviour. Journal of Environmental Psychology, 19, 1-19.
• Hunter, L. M. & Brehm, J. (2003) Qualitative insight into public knowledge of, and concern with, biodiversity. Human Ecology, 31, 309-320.

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Background

The small pelagic fleet use purse-seine nets to target sardines, anchovy and red-eye herring. Vessels are based predominantly in St. Helena Bay, but also use Saldanha Bay, Table Bay, Hout Bay, Gansbaai, Mossel Bay and Port Elisabeth as home ports. This stems from the fact that the historical development of this industry was associated with the distribution the pelagic fish stocks along the west coast in the second half of the 1900’s. Recently there has been a shift in the pilchard stocks eastwards that has resulted in the development of a fleet of small pilchard purse seiners operating out of Mossel Bay and Port Elizabeth. Vessels operating from St Helena Bay and Saldanha Bay often lay up in Hout Bay during the day before fishing again at night. There is also some movement between the south coast harbours and Hout Bay. The fishery operates on a TAC (total allowable catch) and vessels often spend periods of time tied up in port after reaching their TAC for the year.

The fact that vessels move freely between harbours means that they could act as vectors for intra-regional spread of alien species. The fact that they operate from areas that often support international shipping and aquaculture means that there is a substantial risk of them being exposed to alien species and the long layup times when vessels are not operating offer times during which their hulls could be fouled by alien species.

This project will quantify the risk of intra-regional transfer of marine alien species by the small pelagic fleet. In addition, factors contributing to the presence of alien species on pelagic vessels will be identified using CART analysis. These findings will inform management efforts aimed at controlling intra-regional spread of marine alien species.

Requirements

Appropriate degree in ecology, strong analytical and good writing skills.

Key contacts

• Dr Tammy Robinson, Centre for Invasion Biology, Stellenbosch University (trobins@sun.ac.za)

Further reading:

• Floerl O, Inglis GJ, Hayden BJ. 2005. A risk-based predictive tool to prevent accidental introductions of nonindigenous marine species. Environmental Management 35: 765-778.
• Lee JE, Chown SL. 2009 Temporal development of hull-fouling assemblages associated with an Antarctic supply vessel. Marine Ecology Progress Series 386: 97-105.
• Lewis PN, Hewitt CL, Riddle M, McMinn A. 2003. Marine introductions in the Southern Ocean: an unrecognised hazard to biodiversity. Marine Pollution Bulletin 46: 213-223.
• Occhipinti-Ambrogi A, Savini D. 2003. Biological invasions as a component of global change in stressed marine ecosystems. Marine Pollution Bulletin 46: 542–551.
• Olenin S, Minchin D, Daunys D. 2007. Assessment of biopollution in aquatic ecosystems. Marine Pollution Bulletin 55: 379-394.

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Background

The role of marine alien species in altering coastal habitats is well established (Occhipinti-Ambrogi and Savini, 2003), leading to the recognition of the considerable threat that bioinvasions pose to global biodiversity (Olenin et al., 2007). Shipping is widely accepted as the major pathway for such introductions (Lewis et al. 2003), with the most important vectors being ballast water and hull fouling. Despite hull fouling being recognised as a major vector associated with both commercial shipping and recreational yachts, no standard sampling approach for detecting marine alien fouling species has been developed.

This project aims to address this by developing a rigorous and cost effective sampling protocol to detect alien species on the hulls of fishing vessels. This project will consider the use of different sample sizes (i.e. species area curves), different sampling approaches (scrape samples vs visual samples) as well as the effect of depth and position of samples on the hull (i.e. bow vs stern vs side of the vessel).

Requirements

Appropriate undergraduate degree, strong interest in invasion biology, good writing and numerical skills.

Key contacts

• Dr Tammy Robinson, Centre for Invasion Biology, Stellenbosch University (trobins@sun.ac.za)

Further reading:

• Floerl O, Inglis GJ, Hayden BJ. 2005. A risk-based predictive tool to prevent accidental introductions of nonindigenous marine species. Environmental Management 35: 765-778.
• Lewis PN, Hewitt CL, Riddle M, McMinn A. 2003. Marine introductions in the Southern Ocean: an unrecognised hazard to biodiversity. Marine Pollution Bulletin 46: 213-223.
• Occhipinti-Ambrogi A, Savini D. 2003. Biological invasions as a component of global change in stressed marine ecosystems. Marine Pollution Bulletin 46: 542–551.
• Olenin S, Minchin D, Daunys D. 2007. Assessment of biopollution in aquatic ecosystems. Marine Pollution Bulletin 55: 379-394.

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Background

The anemone Sagartia ornata is widely distributed throughout western Europe, the United Kingdom and the Mediterranean, and was first recorded in South Africa 1955 (Mead et al. 2011). To date this anemone has been restricted to the intertidal zone within Langebaan Lagoon (Acuna et al. 2004) where it occurs in densities of up to 426 ± 81 (SD) individuals m–2. At this location the anemone occurs in Spartina maritima beds and on rocks covered by sand (Robinson et al. 2004). This is in contrast to its habitat along British coasts, where it occurs in crevices on rocky shores and on kelp holdfasts. The potential for S. ornata to spread extensively along the west coast, which offers cold water and vast kelp beds typical of its home range has been recognised (Robinson at al 2005) but the impact of this species along our coast has not been considered.

This project aims to:

• Assess the current distribution of this alien anemone.
• Evaluate the ecological impact of this invasion by assessing the effects of this species on sandy shore communities in Langebaan Lagoon.
• Investigate the role of this alien as a predator on South African shores.

Requirements

Appropriate degree in ecology, strong analytical and good writing skills.

Key contacts

• Dr Tammy Robinson, Centre for Invasion Biology, Stellenbosch University (trobins@sun.ac.za)

Further reading:

• Acuna FH, Excoffon AC, Griffiths CL. 2004. First record and redescription of the introduced sea anemone Sagartia ornata (Holdsworth, 1855)(Cnidaria: Actiniaria: Sagartiidae) from South Africa. African Zoology 39: 314-318.
• Acuna FH, Griffiths CL. 2004. Species richness, endemicity and distribution patterns of South African sea anemones (Cnidaria: Actiniaria & Corallimorpharia). African Zoology 39: 193-200.
• Kruger LM, Griffiths CL. 1998. Sea anemones as secondary consumers on rocky shores on the south-western Cape, South Africa. Journal of Natural History 32: 629-644.
• Robinson TB, Griffiths CL 2004. Distribution and status of marine invasive species in and bordering the West Coast National Park. Kudu 47: 79-87.
• Robinson TB, Griffiths CL, McQuaid CD, Ruis M. 2005. Marine alien species of South Africa — status and impacts. African Journal of Marine Science 27: 297-306.

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Background

Predicting the ecological impacts of invasive species, particularly their role in the decline of native species, is a major goal in invasion ecology that has seen little progress (Dick et al in press). However, a new technique is showing great promise in its ability to tell us not only why invasive species impact on native species, but also how we can forecast these impacts; even under changing or different environmental conditions. Quantification of the ‘functional response’ of an organism involves relating the rate of consumption of a resource to the availability of that resource (e.g. predator eating prey). When this is done for invaders as compared to trophically similar natives, we have found that ecologically damaging invaders show higher functional responses than comparator native species (Bollache et al. 2008; Dick et al. in press). The next stage in the development of this new and exciting methodology is to test its application across various taxa (e.g. insects, molluscs, fish, mammals and even plants), ecosystems (e.g. marine, freshwater and terrestrial) and trophic groups (e.g. predators, filter feeders, grazers). This project will examine the functional responses of a variety of invaders in South Africa, some established and some emerging, in comparison to native species. Further, the method will be used to predict how invader impacts may change with environmental change (eg rising temperatures) and between different habitat types (eg natural rivers, canals). The project will also involve training in statistical and modelling techniques and development of these to further explore the use of functional responses in invasion ecology. This project will thus help us to better understand the impact of invasive species in South Africa and provide globally important tests and development of a new predictive methodology in invasion ecology.

Requirements

Appropriate degree in ecology, with good writing and numerical skills.

Key contacts

• Dr Tammy Robinson, Centre for Invasion Biology, Stellenbosch University (trobins@sun.ac.za)
• Prof Jaimie Dick, Queen’s University Belfast (j.dick@qub.ac.uk)
• Dr Olaf Weyl, SAIAB/Centre for Invasion Biology, Stellenbosch University (o.weyl@saiab.ac.za)
• Prof Dave Richardson, Centre for Invasion Biology, Stellenbosch University (rich@sun.ac.za)
• Dr Ruan Veldtman, Dept Conservation Ecology, Stellenbosch University (veldtman@sun.ac.za)
• Dr Cang Hui, Centre for Invasion Biology, Stellenbosch University (chui@sun.ac.za)
• Dr John Wilson, SANBI/Centre for Invasion Biology, Stellenbosch University (jrwilson@sun.ac.za)

Further reading:

• Branch, G.M. & Steffani, C.N. (2004) Can we predict the effects of alien species? A case-history of the invasion of South Africa by Mytilus galloprovincialis (Lamarck). Journal of Experimental Marine Biology and Ecology 300:189-215.
• Bollache, L., Dick, J.T.A., Farnsworth, K.D. & Montgomery, W.I. (2008). Comparison of the functional responses of invasive and native amphipods. Biology Letters, 4: 166-169.
• See: http://www.youtube.com/watch?v=IQ9SkVvmN0M
• Dick, J.T.A. et al. (2010). Parasitism may enhance rather than reduce the predatory impact of an invader. Biology Letters, 6: 636-638.
• Dick, J.T.A. et al. (in press). Ecological impacts of an invasive predator explained and predicted by comparative functional responses. Biological Invasions, (PDF available from: j.dick@qub.ac.uk)
• van Erkom Schurink, C. & Griffiths, C.L. (1993) Factors affecting relative rates of growth in four South African mussel species. Aquaculture 109: 257-273.

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